Wijnen, André J. van

AbstractCancer is a multifaceted disease that involves acquisition of genetic mutations, deletions, and amplifications as well as deregulation of epigenetic mechanisms that fine‐tune gene regulation. Key epigenetic mechanisms that include histone modifications, DNA methylation, and non‐coding RNA‐mediated gene silencing are often deregulated in a variety of cancers. Subnuclear localization of key proteins in the interphase nucleus and bookmarking of genes by lineage commitment factors in mitosis—a new dimension to epigenetic control of fundamental biological processes—is also modified in cancer. In this review, we discuss the various aspects of epigenetic control that are operative in a variety of cancers and their potential for risk assessment, early detection, targeted therapy, and personalized medicine. J. Cell. Physiol. 228: 2103–2108, 2013. © 2013 Wiley Periodicals, Inc.

AbstractVorinostat, an oral histone deacetylase inhibitor with antitumor activity, is in clinical trials for hematologic and solid tumors that metastasize and compromise bone structure. Consequently, there is a requirement to establish the effects of vorinostat on tumor growth within bone. Breast (MDA-231) and prostate (PC3) cancer cells were injected into tibias of SCID/NCr mice and the effects of vorinostat on tumor growth and osteolytic disease were assessed by radiography, micro-computed tomography, and histologic and molecular analyses. Vorinostat-treated and control mice without tumors were also examined. Tumor growth in bone was reduced ∼33% by vorinostat with inhibited osteolysis in the first few weeks of the experiment. However, osteolysis became more severe in both the vehicle and vorinostat-treated groups. Vorinostat increased the expression of tumor-derived factors promoting bone resorption, including PTHrP, IL-8, and osteopontin. After 4 weeks of vorinostat therapy, the non–tumor-bearing contralateral femurs and limbs from vorinostat-treated tumor-free SCID mice showed significant bone loss (50% volume density of controls). Thus, our studies indicate that vorinostat effectively inhibits tumor growth in bone, but has a negative systemic effect reducing normal trabecular bone mass. Vorinostat treatment reduces tumor growth in bone and accompanying osteolytic disease as a result of decreased tumor burden in bone. However, vorinostat can promote osteopenia throughout the skeleton independent of tumor cell activity. Mol Cancer Ther; 9(12); 3210–20. ©2010 AACR.